Tailored Mesoporosity Development in Zeolite Crystals by Partial Detemplation and Desilication

Pérez‐Ramírez, Javier; Abelló, Sònia; Bonilla, Adriana; Groen, Johan C.

doi:10.1002/adfm.200800871

Cited by 203 publications

(154 citation statements)

References 47 publications

(59 reference statements)

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“…This is an evidence of the protective role of TBA + cations during desilication. They are attached at the external surface of the Beta zeolite, since has strong diffusional limitations, and force NaOH to enter pores and then attack the zeolite from inside the structure [39,40]. This resulted in more homogeneous desilication across the zeolite particle, being the external and bulk Si/Al ratios very similar (Table 1).…”

Section: Bulk and Surface Chemical Compositions: Chemical Analyses Anmentioning

confidence: 95%

Catalytic cracking performance of alkaline-treated zeolite Beta in the terms of acid sites properties and their accessibility

Tarach

Góra‐Marek

Tekla

et al. 2014

Journal of Catalysis

161

111

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The zeolite Beta is considered as a promising additive for FCC catalyst in diesel oil production. In this article, it is shown that hierarchical zeolite Beta obtained by an optimized desilication procedure increases Diesel and propylene yields during gas-oil cracking reaction.The alkaline treatment of zeolite Beta (Si/Al = 22) by desilication with NaOH and NaOH&TBAOH was investigated. The catalytic performance improvement of desilicated zeolite Beta has been rationalized by deep characterization of the samples including X-ray diffraction, low temperature adsorption of nitrogen, solid-state 29 Si MAS NMR and IR studies of acidity. Finally, the catalytic performance of the zeolites Beta was evaluated in the cracking of n-decane, 1,3,5-tri-iso-propylbenzene and vacuum gas oil. It was found that desilication with NaOH&TBAOH ensures the more uniform intracrystalline mesoporosity with the formation of narrower mesopores, while preserving full crystallinity resulting in catalysts with the most appropriated acidity and then, with better catalytic performance.

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Section: Bulk and Surface Chemical Compositions: Chemical Analyses Anmentioning

confidence: 95%

Catalytic cracking performance of alkaline-treated zeolite Beta in the terms of acid sites properties and their accessibility

Tarach

Góra‐Marek

Tekla

et al. 2014

Journal of Catalysis

161

111

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“…Mesoporous ZSM-5 zeolites have been advantageously applied for both the alkylation [17][18][19] and the 55 related acylation 20 of aromatic molecules. The choice of accesslimited reactions provides optimal sensitivity to the redistribution of aluminium on alkaline treatment and acid washing through confinement of the alkylation activity to the mesoporous surface.…”

Section: -16mentioning

confidence: 99%

Decoupling porosity and compositional effects on desilicated ZSM-5 zeolites for optimal alkylation performance

Milina

Mitchell

Trinidad

et al. 2012

Catal. Sci. Technol.

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Desilication of conventional zeolites in alkaline medium generates intracrystalline mesoporosity, but inevitably changes other properties such as the Si/Al ratio and aluminium distribution. Assessing the individual effects of porosity, composition, and acidity on the catalytic performance of desilicated zeolites is relevant for their optimal design. Herein, we decouple the respective impacts in the acid-catalysed 10 alkylation of toluene (or cyclohexylbenzene) with benzyl alcohol. These reactions experience strong accessibility constraints to the micropores, providing high sensitivity to the properties of the developed mesopore surface. Through strategic comparison of alkaline-treated ZSM-5 zeolites prepared with and without subsequent acid treatment, we show that while acidity is important, the alkylation activity is dominated by the mesoporous surface area. The selectivity to (methylbenzyl)benzene does not depend on 15 the available external surface. Large mesopore volumes offer no catalytic benefit, and variation in micropore volume has a minimal effect. Acid-treated mesoporous zeolites exhibit higher catalytic activities primarily due to textural enhancements by removal of aluminium-rich amorphous debris. The catalytic results are rationalised on the basis of extensive characterisation (AAS, N2 sorption, XRD, TEM, 27 Al MAS NMR, FTIR, NH3-TPD) and adsorption of toluene and cyclohexylbenzene.

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“…Simulation relies on a range of modeling approaches [37], which are increasingly multiscale [38,39]. Recent possibilities to control pore network properties at multiple length scales via new synthesis methods [40,41,42 ] should be accompanied by theoretical optimization. If the intrinsic catalytic activity per unit nanoporous catalyst is kept constant, as in zeolites or catalytic clusters supported on a mesoporous carrier, then virtually no benefit is gained from a broad macro/mesopore size distribution to increase activity [43,44 ], increase stability [45,46 ] or control selectivity [47]: optimal porosity and optimal average macro/mesopore size are the main parameters.…”

Section: Current Opinion In Chemical Engineeringmentioning

confidence: 99%

A nature-inspired approach to reactor and catalysis engineering

Coppens

2012

Current Opinion in Chemical Engineering

111

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Available online at www.sciencedirect.com A nature-inspired approach to Q1 reactor and catalysis engineering Marc-Olivier Coppens Q2Mechanisms used by biology to solve fundamental problems, such as those related to scalability, efficiency and robustness could guide the design of innovative solutions to similar challenges in chemical engineering. Complementing progress in bioinspired chemistry and materials science, we identify three methodologies as the backbone of nature-inspired reactor and catalysis engineering. First, biology often uses hierarchical networks to bridge scales and facilitate transport, leading to broadly scalable solutions that are robust, highly efficient, or both. Second, nano-confinement with carefully balanced forces at multiple scales creates structured environments with superior catalytic performance. Finally, nature employs dynamics to form synergistic and adaptable organizations from simple components. While common in nature, such mechanisms are only sporadically applied technologically in a purposeful manner. Nature-inspired chemical engineering shows great potential to innovate reactor and catalysis engineering, when using a fundamentally rooted approach, adapted to the specific context of chemical engineering processes, rather than mimicry. Introduction Nature-inspired engineering researches the fundamental mechanism underlying a desired property or function in nature, most often in biology, and applies this mechanism in a technological context. In the context of chemical engineering, we call this approach: nature-inspired chemical engineering (NICE) [1].Application of biological mechanisms to a non-physiological context in reaction engineering requires adaptations, because the relevant time scales and available building blocks are different. Also, we are able to manipulate parameters such as temperature and pressure, which are much less tunable in biology. Hence, like in an abstract portrait, essential aspects of the subject are preserved, but not literally, emphasizing those features that serve a desired purpose. Such features underpin the rational design of an artificial structure that uses the same fundamental mechanism as the natural system. The ultimate implementation is assisted by theory and experimentation. NICE aims to innovate, guided by nature, but it does not mimic nature, and should be applied in the right context.Emphasizing reactor and catalysis engineering, we illustrate how mechanisms used in biology to satisfy complicated requirements, essential to life, are adapted to guide innovative solutions to similar challenges in chemical engineering. These mechanisms include: (1) use of optimized, hierarchical networks to bridge scales, minimize transport limitations, and realize efficient, scalable solutions; (2) careful balancing of forces at one or more scales to achieve superior performance, for example, in terms of yield and selectivity; (3) emergence of complex functions from simple components, using dynamics as an organizing mechanism. Figure 1 presents an overview....

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Tailored Mesoporosity Development in Zeolite Crystals by Partial Detemplation and Desilication

Cited by 203 publications

References 47 publications

Catalytic cracking performance of alkaline-treated zeolite Beta in the terms of acid sites properties and their accessibility

Catalytic cracking performance of alkaline-treated zeolite Beta in the terms of acid sites properties and their accessibility

Decoupling porosity and compositional effects on desilicated ZSM-5 zeolites for optimal alkylation performance

A nature-inspired approach to reactor and catalysis engineering

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